JPH04177173A - Digital storage oscilloscope - Google Patents

Abstract

PURPOSE:To facilitate the observation of a waveform by allowing a vertical axis range and a time axis range to coincide with each other with respect to a displayed waveform by displaying the waveform due to the vertical axis range and the time axis range set at the time of display on the surface of a cathode ray tube. CONSTITUTION:The vertical axis range and the time axis range at the time of the collection of the data corresponding to an input signal to be observed are respectively stored in the first and second memory means 3, 4. The vertical axis and time axis ranges at the time of display are stored in the third and fourth memory means 8, 9. A reading means 12 compares the time axis ranges of the means 4, 9 to read the data stored in a waveform data memory means 10 at the address interval accompanied by the comparison result. A control means 13 operates the ratio of the vertical axis ranges stored in the means 3, 8 and multiplying it by data read from the means 12. The resulting data is stored in a memory means 11 for display as waveform data. A read-out means 14 displays the time axis ranges stored in the means 8, 9 on the surface of a cathode ray tube.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a digital storage oscilloscope. Regarding digital storage oscilloscope display.

(Prior Art) Generally, in a digital storage oscilloscope, an input signal is A/D converted and stored in a memory, and the data is transferred from the memory to a display memory to display a waveform on the screen.

In addition, it has an internal memory for storing waveforms, and the stored waveforms can be recalled any number of times and displayed on the screen.

When storing waveforms in the internal waveform memory, conventional digital storage oscilloscopes either do not import the setting range into the waveform storage device, or even if they do, when displaying the waveform again, the setting range is In many cases, the range display and the displayed waveform range were different.

For example, even if magnification was performed only in the time axis direction and the range display was changed in the vertical direction, there were cases where the displayed waveform was not changed in the vertical direction as shown in Figure 5 (a) and (b). . FIG. 5(a) shows the displayed waveform corresponding to the data stored in the waveform storage device, and FIG. 5(b) shows the displayed waveform corresponding to the data stored in the waveform storage device.
Figure (a) shows the displayed waveform when the time axis range is doubled and the vertical axis range is increased five times. In this case, even though the vertical axis range is five times
The displayed waveform is not expanded vertically, only the time axis direction is
It has been expanded twice.

In addition, there were cases where the displayed waveform was enlarged in the time axis direction, but the range display was not changed. An example of this is shown in Fig. 5(C) compared to Fig. 5(a), where if the range in the time axis direction is doubled, the range in the time axis direction is doubled and the waveform displayed, but the range display has not changed.

Some devices are configured so that the range cannot be changed once the waveform data is stored in the waveform memory.

(Problem to be Solved by the Invention) However, if the above-mentioned conventional waveform display and the range display for the displayed waveform do not match, it is extremely difficult to measure the signal under test from the displayed waveform. There was a problem.

The present invention solves the above problems by enabling expansion and contraction in both the vertical and time axis directions when recalling and displaying a waveform stored in the waveform memory, and displaying the current range at the same time. The purpose is to provide a free digital storage oscilloscope.

(Means for Solving the Problems) As shown in FIG. 1, the digital storage oscilloscope of the present invention has a vertical axis range setting means 1, a time axis range setting means 2, and a data acquisition time corresponding to an observed input signal. The first storage means 3 stores the vertical axis range of , the second storage means 4 stores the time axis range at the time of data acquisition corresponding to the observed human power signal, and the first storage means 3 stores the vertical axis range of . An amplitude adjusting means 5 adjusts the observed input signal level with a gain corresponding to the vertical axis range, and samples the amplitude-adjusted observed input signal at a period corresponding to the time axis range stored in the second storage means 4. A/D conversion means 6 that performs A/D conversion, data acquisition storage means 7 that stores the data converted by the A/D conversion means 6, and third storage means that stores the vertical axis range at the time of display. 8, a first storage means 9 in which the time axis range at the time of display is stored, and a waveform data storage means 10 in which the data stored in the data acquisition storage means 7 is transferred and stored.
, a display storage means 11 in which waveform data for display is stored and from which the stored waveform data is read out at a constant speed; a time axis range stored in the second storage means 4; and a time axis range stored in the first storage means 9. reading means 12 for comparing the vertical axis range and the time axis range stored in the first storage means 3 and reading out the data stored in the waveform data storage means 10 at address intervals according to the comparison result; 3 Calculate the ratio with the vertical axis range stored in the storage means 8,
a control means 13 that multiplies the data read out from the readout means 12 by a value corresponding to the calculated ratio and stores it in the storage means 11 for display as waveform data; and a vertical axis range stored in the third storage means 8. readout display means 14 displays on the cathode ray tube surface the time axis range stored in the first storage means 9; It is characterized by comprising a display means 15 for displaying on the screen.

(Function) According to the digital storage oscilloscope of the present invention configured as described above, the vertical axis range set at the time of data acquisition is stored in the first storage means 3, and the time axis range set at the time of data acquisition is stored. The input signal level to be observed is adjusted by the amplitude adjustment means 5 with a gain stored in the second storage means 4 and corresponding to the vertical axis range stored in the first storage means 3,
The amplitude-adjusted observed input signal is sampled at a period corresponding to the time axis range stored in the second storage means 4 and A/D converted by the A/D conversion means 6, and the A/D converted data is The data is stored in the data collection storage means 7.

On the other hand, when the waveform displayed on the cathode ray tube surface is to be stored in the waveform data storage means 10, the data stored in the data acquisition and storage means 7 is directly transferred from the data acquisition and storage means 7 to create the waveform data. It is stored in the storage means 10. At this time, the vertical axis range is stored in the first storage means 3, and the time axis range is stored in the second storage means 4.

When recalling data corresponding to data stored in the waveform data storage means 10 and displaying a waveform corresponding to the recalled data, a new vertical axis range and time axis range are set. The vertical axis range and time axis range set for display are stored in the third storage means 8 and the first storage means, respectively.
It is stored in the storage means 9.

Next, the reading means 12 compares the time axis range stored in the second storage means 4 and the time axis range stored in the first storage means 9.
The waveform data stored in 0 is read out at address intervals according to the comparison result and is read out by the tag control means 13 to determine the vertical axis range stored in the first storage means 3 and the vertical axis range stored in the third storage means 8. The data read out by the reading means 12 is multiplied by a value corresponding to the calculated ratio and stored in the storage means 11 for display as waveform data. Here, if the waveform data stored in the storage means 11 for display is sequentially read and the waveform is displayed, the vertical axis range stored in the third storage means 8 and the waveform data stored in the first storage means 9 will be displayed. The waveform data is displayed in the time axis range.

The waveform data stored in the storage means 11 for display is read out at a constant speed. The read waveform data is displayed by the display means 15 on the surface of the cathode ray tube as an analog waveform corresponding to the waveform data. Therefore, a waveform corresponding to the vertical axis range corresponding to the data stored in the third storage means 8 and the time axis range corresponding to the data stored in the first storage means 9 is displayed on the surface of the cathode ray tube.

At the same time, a vertical axis range corresponding to the data stored in the third storage means 8 and a time axis range corresponding to the data stored in the first storage means 9 are displayed on the bulla and run bone canal surfaces by the readout display means 14, Similarly, waveforms corresponding to the vertical axis range and time axis range displayed on the cathode ray tube surface are displayed.

(Example) The present invention will be explained below using examples.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention.

The digital storage oscilloscope of this embodiment includes a vertical preamplifier 21 that amplifies the observed input signal applied to the input terminal, an A/D converter 22 that converts the output of the vertical preamplifier 21 into digital data, and an A/D converter 22. Converted digital data.

A memory 23 that stores sweep speed (time/scale) data and vertical axis range (V/division l data, which will be described later), and a waveform memory 24 that stores waveform data.
, a display memory 25 to which the waveform data stored in the waveform memory 24 is transferred and stored; a D/A converter 26 that converts the waveform data stored in the display memory 25 into an analog signal; A final stage amplifier 27 with a constant gain that amplifies the analog signal converted by the D/A converter 26, a cathode ray tube 28 to which the output of the final stage amplifier 27 is supplied and displays its waveform on the screen, a pulse oscillator 33, A variable frequency divider 34 is provided which divides the oscillation frequency of the pulse oscillator 33 and supplies the divided output as a sampling pulse to the A/D converter 22.

Here, for example, the storage capacity of the memory 23 and the waveform memory 24 is set to 16 kW, and the storage capacity of the display memory 25 is set to 2 kW, which is smaller than the storage capacity of the waveform memory 24. is configured to be read out at a constant speed and supplied to the D/A converter 26.

Further, the digital storage oscilloscope of this embodiment includes a ROM 29 storing a program for controlling the digital storage oscilloscope, a CPU 30 controlled by the program stored in the ROM 29, and a RAM 31 having a work area. A waveform instruction switch 321, a time axis range selection switch 321, and a vertical axis range selection switch 32 provided on the operation panel 32
Upon receiving the instruction and selection range information from ゜, A/D conversion is performed by gain control of the vertical preamplifier 21 and frequency division ratio control of the variable divider 34 under the control of the CPU 30 according to the instruction and selection range information. The time of the displayed waveform is controlled by controlling the frequency of the sampling pulse in the device 22, controlling the magnification of digital data stored in the waveform memory 24, and controlling the transfer of waveform data stored in the display memory 25. It is configured to perform waveform display control and range display readout control corresponding to the axial range and vertical axis range.

Memory 23, waveform memory 24, and display memory 25
may be formed in the RAM 31.

The case where a waveform is recalled from the waveform memory and displayed will be described below in accordance with the program stored in the ROM 29 and with reference to the flowchart shown in FIG.

In normal operation, the vertical range selection switch 32
．． The vertical axis range data selected by and the time axis range data instructed by the time axis range selection switch 32□ are read, and the read vertical axis data and time axis data are stored in the memory 23 and read. The vertical preamplifier 21 is controlled to a gain corresponding to the vertical axis range data, and the observed input signal is amplified.The amplified observed input signal is sampled with a sampling pulse of a frequency corresponding to the read time axis data. , A/D converter 22 performs A/D conversion, and the converted digital data is stored in memory 23. The digital data and range data are transferred to a display memory 25, converted into analog signals by a D/A converter 26, amplified by a final stage amplifier 27, and displayed on the surface of a cathode ray tube 28.

Next, the case where waveform data is stored in the waveform memory 24 will be explained with reference to the flowchart shown in FIG. 3(a).

By executing the program, it is checked whether a waveform storage instruction has been issued by pressing a waveform storage instruction switch (not shown) provided on the operation panel 32 (step S,
), if it is determined in step s1 that no waveform instruction has been given, other processing is executed.

When it is determined in step S that a waveform storage instruction has been given, the vertical axis range data and time axis range data set at that time are stored in the waveform memory 24 (step s2), and the digital data is transferred from the memory 23. Transferred to and stored in the waveform memory 24 (step s
,).

The case where a waveform corresponding to the data stored in the waveform memory 24 is displayed on the screen will be explained with reference to the flowchart of FIG. 3(b).

When the program is executed, it is checked whether or not a waveform memory recall instruction has been issued by the waveform instruction switch 32 (step s4). If it is determined in step S4 that a waveform memory recall instruction has not been issued, other Processing is executed.

If it is determined in step S4 that a waveform memory recall instruction has been issued, then step S4 is followed by vertical axis range selection switch 32. The vertical axis range data selected by is read as vertical axis data for display and stored in the RAM 31 (step S). Following step S, the vertical axis range data stored in the waveform memory 24 is read out, and the vertical axis range data is combined with the vertical axis range data stored in step S6 as the vertical axis range data for display. The ratio is calculated and stored in the RAM 31 (step S). The ratio calculated in step S8 indicates the ratio between the vertical axis range when the observed input signal data is acquired and the vertical axis range when the waveform memory is displayed.

Following step S, digital data is read from the waveform memory 24, and the read digital data is multiplied by the calculation ratio stored in the RAM 31 in step S and stored in the RAM 31 as waveform data (step S7). ). Therefore, suppose that the vertical axis range is 0. 5 ■ / scale is set, step S
, the digital data stored in the waveform memory 24 will be multiplied by (1/2) and stored in the RAM 31 in step S. If the RAM is doubled
31.

Therefore, the waveform data stored in the RAM 31 has been converted for display. The same applies to other vertical axis range data. As a result, R.A.
When the waveform corresponding to the waveform data stored in M31 is displayed on the screen of the cathode ray tube 28, the displayed waveform corresponds to the vertical range read in step S6 in the vertical axis direction.

Following step S7, the time axis range selection switch 32
．． The time axis range data selected by is read as the time axis range data when calling the waveform memory and displaying, and the read time axis range data is stored in the RAM 31.
(step S). Following step S, the ratio of the time axis range data read in step S and the time axis range data read in step S2 is calculated, addresses are specified according to the calculation result, and waveform data is transferred from the RAM 31. read out,
It is stored in the display memory 25 (step S and step S1°). Step S.

The waveform data stored in the display memory 25 is then read out at a predetermined constant speed, converted into an analog signal by the D/A converter 26, amplified by the final stage amplifier 27, and then sent to the cathode ray tube 28. The waveform of the analog signal is displayed on the screen (step S4). Step Sll followed by R
The time axis range corresponding to the time axis range data and the vertical axis range corresponding to the vertical axis range data stored in the AM 31 are read out and displayed on the screen of the cathode ray tube 28 (step S, 2). The lead-out display method in steps S and 2 is the same as in the conventional case, but
It is clear from the above that the displayed range is for the currently displayed waveform.

Here, reading of waveform data from the RAM 31 and writing of the waveform data to the display memory 25 in step SIO will be described.

It is assumed that 10 scales are carved in the time axis direction of the tube surface of the cathode ray tube 28, and 200 points of data are displayed on each scale. Since the storage capacity of the display memory 25 is 2 kW, when the time axis range is 1 ms/division, almost the entire storage content of the display memory 25 is displayed on 10 scales.

1ms as time axis range data in step S2.
It is assumed that 2 ms/scale is written in step S, and 2 ms/scale is written in step S. In this case, R.A.
The memory contents of M31 are read out every other address, that is, every two addresses, and stored in the display memory 25. Therefore, in this case, when the time axis range is 1 ms/division, all the waveform data stored in the display memory 25 is displayed approximately at 10 time axis divisions;
The time axis is displayed approximately at 5 scales due to the 2ms/scale,
The time axis range becomes 172.

Further, for example, it is assumed that 1 ms/division is written as time axis range data in step S2, and 5 ms/division is written in step S. In this case, the memory contents of the RAM 31 are every 4 addresses,
That is, the data is read every five addresses and stored in the display memory 25.

Therefore, in this case, when the time axis range is 1 ms/division, all the waveform data stored in the display memory 25 is displayed approximately on the time axis 1o scale;
Because of the s/scale, the time axis is displayed with two scales, and the time axis range is 115.

2ms as time axis range data in step S2.
It is assumed that 1 ms/scale is written in step S, and 1ms/scale is written in step S. In this case, R.A.
Each time the stored contents of M31 are read by one address, the previous value is interpolated, that is, one address of RAM 31 is subsequently read out substantially twice and stored in the display memory 25. Therefore, when the time axis range is 2 ms/division, 20 divisions are required to display a waveform that is displayed in 10 divisions, and the time axis range is doubled.

To illustrate this case, the vertical axis range is 06IV/division, and the time axis range is 10rr+s/division, which are stored in the waveform memory 24, and when displayed, the vertical axis range is O,
When the IV/scale is set and the time axis range is 10m5/scale, the displayed waveform is as shown in Figure 1 (a),
When the vertical axis range is changed to 50 mV/division and the time axis range is changed to 5 ms/division at the time of display, the displayed waveform is as shown in FIG. 1(b).

Furthermore, instead of previous value interpolation, average value interpolation may be used that uses the average value of waveform data stored in two consecutive addresses.

Furthermore, it can be easily inferred that cases where the time axis range and the vertical axis range other than those mentioned above are set respectively.

(Effects of the Invention) As explained above, according to the present invention, the vertical axis range and time axis range set at the time of display and the waveform according to the vertical axis range and time axis range are displayed on the surface of the cathode ray tube. , the displayed waveform and the vertical axis range and time axis range for the displayed waveform match,
This has the effect of eliminating inconvenience in waveform observation.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing the configuration of the present invention. FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention. FIG. 3 is a flowchart for explaining the operation of one embodiment of the present invention. FIG. 1 is a waveform diagram showing an example of a display waveform according to an embodiment of the present invention. FIG. 5 is a display waveform diagram according to a conventional example. 1... Vertical axis range setting means, 2... Time axis range setting means, 3.4.8 and 9... First, second, third
and first storage means, 5...amplitude adjustment means, 6...
A/D conversion means, 7... data guard storage means, 1°.
... Waveform data storage means, 11... Storage means for display, 12... Reading means, 13... Control means, 14
...Leadout display means, 15...Display means.

Claims (1)

[Claims] a vertical axis range setting means, a time axis range setting means, a first storage means storing a vertical axis range at the time of data acquisition corresponding to the observed input signal, and a first storage means at the time of data acquisition corresponding to the observed input signal. a second storage means for storing a time axis range of the first storage means; an amplitude adjustment means for adjusting the observed input signal level with a gain corresponding to the vertical axis range stored in the first storage means; and an amplitude adjusted observation input signal level. A/D conversion means for sampling and A/D converting the signal at a period corresponding to the time axis range stored in the second storage means; and a data acquisition memory for storing data converted by the A/D conversion means. a third storage means in which the vertical axis range at the time of display is stored; a first storage means in which the time axis range at the time of display is stored; and a waveform to which the data stored in the data acquisition storage means is transferred and stored. a data storage means; a display storage means in which waveform data for display is stored and the stored waveform data is read out at a constant speed; and a time axis range stored in the second storage means;
reading means for comparing the time axis range stored in the storage means and reading out the data stored in the waveform data storage means at address intervals according to the comparison result; and a vertical axis range stored in the first storage means. and the vertical axis range stored in the third storage means, and the data read out from the readout means is multiplied by a value corresponding to the calculated ratio and stored as waveform data in the storage means for display. a control means, a readout display means for displaying the vertical axis range stored in the third storage means and the time axis range stored in the first storage means on the cathode ray tube surface; and a readout display means for displaying the vertical axis range stored in the third storage means and the time axis range stored in the first storage means; A digital storage oscilloscope, comprising display means for displaying analog waveforms corresponding to waveform data being displayed on a cathode ray tube surface.